P2 on the yellow connector is power to your flasher relay, radio, cigarette lighter, clock and a few other things. So it explains your clock stopping and flashers not coming on.

However, it has nothing to do with the engine.

Did you check the green connector in the engine room? Pin 5 carries ignition (thick grey wire). It's supplied via the grey connector next to the fuse box. It's pin 6 there. That should allow you to trace the ignition power feed back to the source (the key lock if necessary).

By checking that pin, which was 12v, I must have cleaned the pins, because when I reconnected it, it started!Strange, because yesterday I had sprayed contact cleaner into the connector, but I guess it needed a wiggle or two.I will get that connector replaced as it is very dirty and could be corroded. I'll also take those readings that Oetker suggested, tomorrow.

My indicators and clock now work too, although they don't flash. I guess the relay needs replacing.

It ran really well, but I suspect I haven't solved the intermittent mis-firing yet, unless that bad green connection could cause that too?

This readings are no longer needed, because the engine is running.I think that the connectors at the fusebox are also the cause of misfiring.My car has all wires on fusebox that are on the steerside permantly connected with solder.Last ownwer before me did that, because of same sort of problems you have..